Journal of biophotonics最新文献

Transcranial photobiomodulation (PBM) was evaluated in a bilateral common carotid artery stenosis mouse model of chronic cerebral hypoperfusion. PBM enhanced cognitive performance and regional cerebral blood flow, particularly in hippocampal and cortical regions. Histological analysis revealed attenuated neuronal loss and smaller perivascular spaces, although residual necrotic foci persisted. PBM reduced BCL2 expression and modulated HIF-1 in a context-dependent manner, suggesting neuroprotection via BCL2-independent and hypoxia-responsive pathways. These results support PBM as a noninvasive approach for mitigating cognitive decline in chronic hypoperfusion and warrant longitudinal, mechanistic studies to define its therapeutic parameters.

Seborrheic keratosis is a common benign skin tumor. None of the current conventional testing techniques can assess the mechanical properties of the tissue, such as hardness, elasticity and viscoelasticity. In this study, we investigated the morphological and elastic properties of seborrheic keratosis (SK), a common benign skin tumor, using optical coherence elastography (OCE). We found that the OCE technique was able to distinguish SK tissue from normal tissue. In addition, by measuring skin elasticity, it was possible to identify SK lesions with different clinical types and dermoscopic patterns of presentation. As a non-invasive quantitative tool, OCE demonstrates significant potential in the clinical diagnosis and assessment of skin aging diseases, providing objective evaluations based on elasticity.

Photobiomodulation (PBM) with red or near-infrared (NIR) light enhances mitochondrial metabolism and tissue repair, yet its safety regarding malignant cells remains under debate. This study examined wavelength- and fluence-dependent PBM effects on skeletal muscle and cancer cells. Murine myoblasts (C2C12) and human lung adenocarcinoma cells (A549) were exposed to 660 nm LED or 830 nm NIR laser light at 0-20 J/cm². Viability (CCK-8), reactive oxygen species (ROS), and ATP levels were quantified. PBM produced a biphasic response in C2C12, with maximal viability and ATP at 5 J/cm² under NIR and moderate ROS elevation. Conversely, A549 showed stable or slightly reduced viability despite increased ROS, suggesting a distinct redox sensitivity. Both wavelengths enhanced mitochondrial activity in muscle cells while avoiding overstimulation in carcinoma cells. These wavelength- and cell type-specific effects indicate the bioenergetic safety of PBM and its potential for muscle regeneration research.

Background: Clear cell renal cell carcinoma (ccRCC), the most common aggressive renal cancer subtype, shows marked heterogeneity that hinders recurrence prediction.

Objective: To evaluate hyperspectral pathology imaging (HSI) with deep learning for individualized recurrence risk prediction in ccRCC.

Methods: Slides from 48 patients with ccRCC were imaged using a 400-1000 nm hyperspectral microscope. Spectral data were preprocessed, and a dual-branch network (HSI-FusionNet) extracted spatial and spectral features via 2D and 1D convolution, followed by gated fusion and multiple instance learning (MIL) for patient-level prediction.

Results: HSI-FusionNet achieved strong test performance (area under the receiver operating characteristic curve [AUC] = 0.912; sensitivity = 0.881; specificity = 0.846), outperforming ResNet-50, 1D-Convolutional Neural Network (CNN), and a 1D-Transformer. Recurrence-related spectral bands (530-580 and 830-900 nm) reflected hemoglobin and lipid-collagen differences.

Conclusion: HSI with deep learning accurately identifies recurrent ccRCC and reveals molecular-metabolic signatures, supporting precision postoperative risk stratification.

Age-related macular degeneration is a disease that affects the middle part of the vision and involves pathological alterations in the retinal pigment epithelium. Accurate and timely evaluation of the retinal pigment epithelium is a cornerstone of effective treatment planning. In this study, we present the development of a preclinical method for early diagnostics of age-related macular degeneration using time and spectral characteristics of fluorescence of lipofuscin granules from the retinal pigment epithelium. Using the unique system based on a superconducting single-photon detector and time-correlated single-photon counting electronics integrated in the confocal laser scanning microscope we determined the parameters of fluorescence (distribution long and short fluorescence lifetime components and their contribution to the total fluorescence signal as well as fluorescence spectral shift) that have a diagnostic value for differentiation of the normal and pathological states in the degenerative diseases of the retina and retinal pigment epithelium.

Laser treatment of natural canals is typical for phlebology, gynecology and urology. This method has several problems, including the choice of light dosimetry and instrumentation. It is important to provide a reliable and uniform energy distribution on the canal walls. Aimed at this, a sapphire tip is proposed in this work. Manufactured by the crystal growth technique, this tip has miniature dimensions and an axial cavity, which serves as a reflecting element. It can be combined with standard optical fibers providing contact coagulation. In this work, the performance of this instrument was studied numerically and experimentally, using ex vivo liver samples. The results reveal an ability of the tip to form local coagulation without a sharp increase in temperature on the instrument surface. Thus, the sapphire tip demonstrates significant prospects for interstitial laser treatment, combining simple design, high reliability, reproducibility of the light distribution, and a smoothed thermal profile.

Accurate identification of dysplasia in Barrett's esophagus (BE) remains a challenge. Advanced optical imaging techniques may allow for better localization of dysplasia in BE. Here, we have assessed the potential clinical utility of a previously described multimodal imaging probe combining optical coherence tomography (OCT) with angle-resolved low coherence interferometry (a/LCI) to prospectively identify dysplasia in BE. Imaging was conducted on 37 patients undergoing endoscopic surveillance of BE, yielding co-registered biopsies of 50 esophageal sites. The a/LCI nuclear morphology data were compared to a previous decision line to prospectively predict dysplasia, demonstrating 100% sensitivity, 93% specificity, and 94% overall accuracy. The NPV was 100%, comparable to previous a/LCI studies. The addition of OCT imaging markedly improved PPV and specificity, compared to previous studies with a/LCI alone, illustrating the clinical utility of the combined platform. These findings suggest that combining OCT and a/LCI enables better detection of dysplasia by providing better guidance.

We present a tunable polarization imaging system (TPS) incorporating a liquid crystal polarization grating (LCPG) and a quarter-wave plate (QWP). TPS overcomes low diffraction efficiency and insufficient flexibility in polarimetric imaging, leveraging the LCPG's high diffraction efficiency (> 98%) and polarization control via LCPG-QWP combination. Using the TPS, we conducted comparative experiments on five types of pathological tissue sections, employing six types of polarized light alongside unpolarized light (serving as the control group), and acquired polarization images. Furthermore, we applied multidimensional data analysis methods to analyze and compare the obtained polarization images. The results show that polarized light significantly enhances texture contrast in diseased tissues, achieving a 284% increase compared to acquisitions using unpolarized light, while enabling robust discrimination between benign and malignant tissues. TPS, characterized by its high efficiency, compact design, and compatibility with existing equipment, shows great potential for label-free, pathological-section-based early cancer diagnosis.

Photobiomodulation (PBM) a promising non-invasive therapeutic technique has been proposed to have regenerative ability. There is limited understanding of PBMs effectiveness in 3D cell culture systems. To evaluate the effect of PBM at 825 nm on adipose-derived stem cells (ADSCs) cultured in 2D and 3D spheroid models. ADSCs were exposed to PBM at fluences of 5, 10, and 15 J/cm² to assess cellular responses. Cell morphology, spheroid diameter, cell concentration, viability, proliferation, and cytotoxicity were monitored 24- and 72-h post-irradiation (hpi). In 2D cell culture, PBM at 5 J/cm² showed a significant increase in cell viability and proliferation. Cellular cytotoxicity was higher in 2D. Spheroids maintained steady size, increased viability, and proliferation peaking at 24 hpi but remaining stable over time at 10 J/cm². 2D cell cultures show an over expression of PBM-induced effects, while spheroids provide a more physiological and balanced response profile particularly at 10 J/cm².

Fourier-transform infrared (FTIR) spectroscopy was used to investigate molecular differences among peritoneal, ovarian, bowel endometriosis phenotypes and control tissues. Peritoneal lesions showed the most pronounced spectral changes in CH-stretching (2800-3000 cm^-1) and 1000-1500 cm^-1 regions, indicating protein and lipid alterations. Bowel lesions exhibited moderate but significant deviations, particularly in protein- and nucleic acid-associated bands, while ovarian lesions displayed subtler differences with increased lipid-related CH-stretching. Principal component analysis distinguished all phenotypes from controls, with peritoneal clustering most distinct, bowel intermediate, and ovarian partially overlapping. Key discriminative regions included phosphate vibrations (1080-1100, 1240-1250 cm^-1), CH₂ bending (~1450 cm^-1), amide I (~1650 cm^-1), and amide II (~1540 cm^-1). Decision tree analysis identified phenotype-specific markers: 988 cm^-1 (ovarian), 1101 cm^-1 (bowel), 1544 cm^-1 (peritoneal). Marker intensity correlated with tumor size and clinical scores, strongest in ovarian lesions. These findings highlight phenotype-specific FTIR fingerprints, offering diagnostic and prognostic potential in endometriosis.